Continuous-casting mold with thin-walled copper liner

ABSTRACT

A continuous-casting mold in which the steel backing plates are fastened to the copper liner with studs welded to the liner. The welded construction enables a thinner-walled liner to be used and affords better resistance against heat distortion and thermal stresses. The studs may be welded directly to the liner or to stainless steel strips which in turn are welded to the liner.

United States Patent 91 Bower, Jr.

[ 1 Jan. 9, 1973 [54] CONTINUOUS-CASTING MOLD WITH T HIN-WALLED COPPERLINER [75] Inventor: John E. Bower, Jr., Monroeville Borough, Pa.

[73] Assignee: United States Steel Corporation [22] Filed: Nov. 2, 1970i [21] Appl. No.1 85,848

[52] US. Cl ..164/283, 249/135 [51] Int. Cl. ..B22d 11/02 [58] Field ofSearch ..164/273 R, 283; 249/135;

[56] References Cited UNITED STATES PATENTS Kiefer ..220/63 R 3,618,658ll/1971 Gallucci ..164/283X FOREIGN PATENTS OR APPLICATIONS 962,2597/1964 Great Britain ..164/283 1,191,833 5/1970 Great Britain ..164/273Primary ExaminerRobert D. Baldwin Attorney-Walter P. Wood [57] ABSTRACTA continuous-casting mold in which the steel backing plates are fastenedto the copper liner with studs welded to the liner. The weldedconstruction enables a thinner-walled liner to be used and affordsbetter resistance against heat distortion and thermal stresses. Thestuds may be welded directly to the liner or to stainless steel stripswhich in turn are welded to the liner.

5 Claims, 4 Drawing Figures PATENTEDJAN 9 I975 SHEET 2 [IF 2 lNVE/VTORJOHIVE BOWL R JR.

Attorney CONTINUOUS-CASTING MOLD WITH THIN- WALLED COPPER LINER Thisinvention relates to an improved mold for continuously casting metals.

A conventional continuous-casting mold is a doublewalled open-endedsleeve. The inner wall or liner usually is formed of copper to furnishmaximum thermal conductivity, and the outer wall or backing is formed ofsteel plates to furnish mechanical strength. Liquid metal is poured intothe top of the mold and a partially solidified casting emergescontinuously from the bottom. Channels are formed between the backingand liner through which water circulates to cool the liner and assist insolidifying the casting. The channels may be machined into either thecopper liner or steel backing, but preferably into the latter toconserve copper which is more costly. It is of course necessary tofasten the backing plates and liner together. I-Ieretofore the practicehas been to drill and tap openings in the outside faces of the copperliner and thread studs, usually steel, into these openings. The studsextend through mating openings in the backing plates and carry nutswhich hold these plates in place. The conventional constructionnecessitates the use of a relatively thick-walled liner to affordsupport for the studs, but this creates an undesirable stress pattern,as well as utilizing a large quantity of copper.

An object of my invention is to provide an improved continuous-castingmold which enables me to diminish the wall thickness of the copperliner, thus affording a better stress pattern and using less copper.

A more specific object is to provide an improved mold in which I weldthe studs to the copper liner, either through the use of intermediatestrips or directly.

In the drawings:

FIG. 1 is a. simplified exploded perspective view of one form of moldconstructed in accordance with my invention;

FIG. 2 is a vertical section through the double-wall of the mold showinga modification;

FIG. 3 is a section similar to FIG. 2, but showing another modificationand FIG. 4 is a horizontal section through the double-wall of the moldshowing a further modification.

FIG. 1 shows a continuous-casting mold which includes a copper innerwall or liner l and an outer wall or backing formed of steel side plates12, end plates 13 and corner bars 14. The liner illustrated is ofone-piece welded construction and has a relatively thin wall, preferablyabout inch thick. A plurality of vertical channels 15 are machined inthe inside faces of the side and end plates 12 and 13, leaving ribs 16between channels. The channels serve as passages for circulating waterto cool the liner. The lower and upper ends of the channels have waterinlets and outlets, which are arranged in the usual fashion but are notshown since they are not involved in the present invention. A pluralityof shallow vertical channels 17 are machined in the outside faces ofliner at locations opposite ribs 16. I weld stainless steel strips 18 inthese channels. The strips preferably are about 3/16 inch thick and of amaximum width of about 1 inch, and in this embodiment are continuousfrom the top to the bottom of the liner. To each strip I weld a row ofvertically spaced studs 19, preferably also of stainless steel.Preferably I emplo an electron beam to weld strips 18 in channels 17 ana conventional welding gun to weld studs 19 to the strips. The side andend plates 12 and 13 have openings 20 through their ribs 16 to receivethe studs. Nuts are threadedly engaged with the ends of the studsoutside the plates to hold the parts assembled. I attach the corner bars14 with threaded connectors (not shown) to afford handling and torsionalrigidity to the assembled mold.

FIG. 2 shows a modification in which the stainless steel strips are indiscontinuous sections 23 with gaps 24 therebetween. The nuts on thestuds are countersunk in the outside of the plates. The same countersunkarrangement also can be used with the embodiment shown in FIG. 1. Inother respects the embodiment of FIG. 2 is similar to that of FIG. 1;hence I have not repeated the description.

FIG. 3 shows another modification in which I weld studs 26 directly tothe copper liner 27.

FIG. 4 shows another modification in which I apply the principles of myinvention to a four-piece copper liner. The liner includes end members29 which abut the inner faces of side members 30. This constructionenables the liner to be adjusted to cast different sizes of product, asknown in the art.

In each instance I use a thin-walled liner, which not only conservescopper but affords better resistance against heat distortion and thermalstresses than a liner with thicker walls. The stainless steel strips 18or 23 have approximately the same coefficient of expansion as the copperliner. The strips of FIGS. 1 and 2 distribute the load on the studs overa greater area of the liner than directly welded studs of FIG. 3, butthe latter offers better heat transfer. The discontinuous strips of FIG.2 allow greater flexibility of the mold and increase the capacity of themold to absorb thermal distortions over the continuous strips of FIG. 1.

I claim:

1. In a continuous-casting mold which includes a relatively thin-walledcopper liner of a thickness of about inch, steel backing plates outsidesaid liner and having vertical channels in their inside faces forcirculating water and ribs between channels, and means fastening saidplates to said liner, the improvement in which s'aidfasteningmeans-includes stainless steel strips, a plurality of studs welded toeach of said strips, and nuts threadedly engaging said studs, said linerhaving vertical channels in its outside face opposite said ribs, saidstrips being welded in said second-named channels, said studs extendingthrough openings in said ribs, said nuts being located outside saidplates.

2. A mold as defined in claim 1 in which said strips are continuous fromthe top to the bottom of said liner.

3. A mold as defined in claim 1 in which said strips are in sectionswith gaps between sections.

4. A mold as defined in claim 1 in which said liner is of one-piecewelded construction.

5. A mold as defined in claim 1 in which said liner is of four-piececonstruction with end walls abutting side walls.

1. In a continuous-casting mold which includes a relatively thin-walled copper liner of a thickness of about 3/8 inch, steel backing plates outside said liner and having vertical channels in their inside faces for circulating water and ribs between channels, and means fastening said plates to said liner, the improvement in which said fastening means includes stainless steel strips, a plurality of studs welded to each of said strips, and nuts threadedly engaging said studs, said liner having vertical channels in its outside face opposite said ribs, said strips being welded in said second-named channels, said studs extending through openings in said ribs, said nuts being located outside said plates.
 2. A mold as defined in claim 1 in which said strips are continuous from the top to the bottom of said liner.
 3. A mold as defined in claim 1 in which said strips are in sections with gaps between sections.
 4. A mold as defined in claim 1 in which said liner is of one-piece welded construction.
 5. A mold as defined in claim 1 in which said liner is of four-piece construction with end walls abutting side walls. 